Altitude Correction Table

Altitude Correction Table

Altitude (Feet)

Airflow Correction Factor

BTUH Correction Factor

1,000

0.98

1.00

2,000

0.95

0.99

3,000

0.93

0.98

4,000

0.91

0.97

5,000

0.89

0.96

6,000

0.87

0.95

7,000

0.85

0.94

8,000

0.81

0.93

The performance of mechanical cooling systems will be negatively impacted as altitudes increase because of reduced
mass flow rate of the lower density air. In the table, we provide correction factors for airflow and BTUH at various
altitudes—these correction factors should be applied when sizing our cooling systems. Please contact us for more information.

Airflow Correction Factor

As altitudes increase, fans produce reduced mass flow rates of lower density air, causing the cooling unit to be less
efficient on both ends of the cooling system. On the cold side, the SST (saturated suction temperature) will be lower than
optimal, and on the hot side, the SCT (saturated condensing temperature) will be higher than optimal. The airflow correction
factors are provided for informational purposes.

BTUH Correction Factor

The reduced airflow will cause the cooling unit's BTUH performance to be diminished according to the correction factors
listed above. For example, CellarPro 1800XTS cooling unit, which produces 1886 BTUH at 55°F at sea level, would produce
1754 BTUH (ie correction factor of 0.93) at an altitude of 8,000 feet.